In the operation of an automotive vehicle the engine creates torque during periods of acceleration and deceleration. For engines which are aligned so that the crankshaft extends along the length of the vehicle, conventional connections between the engine manifold and the exhaust system are able to absorb the torque without problems. For engines arranged along a transverse axis, however, the torque stresses the normally rigid connection between the engine manifold and the exhaust system, which can eventually cause fatigue cracking of the engine manifold.
To prevent the transmission of torque forces to the engine manifold, it is necessary to replace the normally rigid connection between the engine manifold and the exhaust system with one that does not transmit the torque forces. This typically has been accomplished through use of a ball and socket joint, which allows the angle between the manifold and the exhaust system to vary without transmitting undesirable stresses to the engine manifold. Although this arrangement has been successful in preventing fatigue cracking of the manifold, the joint is not able to contain the exhaust gases, allowing them to leak out into the atmosphere without passing through the catalytic converter. This creates the potential danger of leaked exhaust gases entering the passenger compartment of the vehicle.
Further drawbacks in conventional coupling arrangements are the lack of thermal insulation in the connection between the engine manifold and the exhaust system and the high cost of such connectors.
It would be desirable to be able to unload the engine manifold from exhaust system torque in a more reliable and efficient manner, and to do so at a more economical cost.